Showing papers on "Trickling filter published in 1986"

Comparative removal of toxic pollutants by six wastewater treatment processes

Abstract: Five pilot-scale wastewater treatment processes that provided less than secondary treatment - primary clarification plus filtration, chemical clarification, high-rate trickling filter, aerated lagoon, and facultative lagoon - were evaluated for removal of priority pollutants from municipal wastewater. A conventional activated sludge system was operated in parallel as a control. Wastewater feed was spiked with 21 organics dissolved in toluene. Removal of ambient concentrations of live metals was also evaluated. The control typically removed 80 to 90% of volatiles and 85 to 95% of semivolatiles. The facultative lagoon was the best alternative process, followed by the aerated lagoon. Removals of a specific toxic pollutant depended on the properties of the chemical and its interactions with removal mechanisms used in each treatment process. 9 references, 2 tables.

Nitrification in trickling filters

Abstract: Les facteurs influencant la nitrification sont la charge organique, la competition entre les organismes heterotrophes et les bacteries nitrifiantes, l'assimilation de l'ammoniac et la denitrification. La charge organique totale par unite de surface du materiau permet de prevoir la performance de nitrification

Mathematical Models in Biological Wastewater Treatment

Abstract: Introduction (S.E. Jorgensen, M.J. Gromiec). Principles of mathematical modelling of biological wastewater treatment processes (V.A. Vavilin). Comprehensive activated sludge process design (W.W. Eckenfelder et al.). Modelling of effluent quality control for activated sludge plants (P.E. Sorensen). Mathematical model for dual power level, multicellular (DPMC) aerated lagoon systems (L.G. Rich). Mathematical models for waste stabilization ponds (J.J. Fritz). Mathematical models for the trickling filter process (J. Roberts). A loading model for biological attached growth reactors - development and application (J.A. Oleszkiewicz). Mathematical models for the oxygen transfer processes in rotating biological contactors (T. Matsuo, K. Yamamoto). Mathematical modelling of nitrification and denitrification in rotating biological contactors (Y. Watanabe). Mathematical modelling of biological packed and fluidized bed reactors (S.W. Hermanowicz, J.J. Ganczarczyk). Mathematical models for biological aerobic fluidized bed reactors (S. Elmaleh, A. Grasmick). Mathematical modelling of the anaerobic digestion process (K. Hanaki et al.). Mathematical models in anaerobic treatment processes (A. Rozzi, R. Passino). Mathematical modelling of energy consumption in biological wastewater treatment (H. Kubota, K. Fujie). Mathematical models for cost-effective biological wastewater treatment (D. Tyteca).

Design of trickling filter nitrification towers

Abstract: Les courbes de conception doivent prendre en compte 4 parametres critiques: la charge hydraulique, l'azote des eaux brutes, les effets du recyclage et la temperature de l'eau usee

Evaluation of plastic media in trickling filters

Abstract: Des differences dans les performances des milieux sont attribuees aux differents temps de contact qui sont determines par les caracteristiques de distribution de flux et de saturation du milieu ou d'engagement du systeme de circulation

Aeration and substrate utilization in a sparged packed-bed biofilm reactor

Abstract: Recently, much attention has been focused on the use of bio logical fixed-film reactors for wastewater treatment. This is pri marily because of their simple operation, and reduced reactor volume and land area requirements. Submerged, fixed-film packed-bed reactor designs have recently been developed that use relatively small media sizes to further reduce reactor vol ume.1,2 Such reactors require air sparging to supply sufficient oxygen for relatively high substrate removal rates associated with the high biomass concentration per unit reactor volume. A typ ical example is the biological aerated filter. As shown in Figure 1, primary effluent is applied downward through a 1.8-m bed of fired clay media (2.5 to 4-mm size). Air is sparged into the bed and the bed is backwashed to remove excess solids. Typical hydraulic retention times to achieve 90% or more biochemical oxygen demand (BOD) removal are 40 to 60 minutes with vol umetric organic loadings of 3 to 5 kg/m3 d BOD (190 to 310 lbs/day/1000 ft3).1'2 In the past, mathematical mechanistic models have been de veloped to describe substrate utilization in biofilm reactors.3"11 Some of these models have also recognized that substrate removal rates in the biofilm can be controlled by substrate or oxygen concentration, or both.3-9 For systems described by such models, oxygen has usually been supplied by preoxygenation of the in fluent with air or pure oxygen. This is not the case for sparged packed-bed biofilm reactors because oxygen is continuously supplied and used.

Process and apparatus for biologically treating water, preferably presettled waste water

Abstract: In a process and an apparatus for the biological purification of water with the aid of a closed trickling filter which is operated with pure oxygen and/or air, and with a downstream upwards filter with floating matter and intermittent flushing, the saturation of the gas blanket which mainly contains oxygen in the pressure trickling filter is controlled by choosing the operating pressure so that the oxygen supply on the one hand corresponds to the biochemical oxygen demand of the water, and the on the other hand a residual oxygen content dissolved in the water makes continuation of a biological final purification in the upwards filter possible, and thus replaces conventional final clarification.

Process and apparatus for the biological purification of waste waters which are produced seasonally in a greatly increased amount and/or with a greatly increased dirt load

Abstract: In order to be able to process waste waters (effluents) produced seasonally, e.g. in vineyards and winemakers', in a light load activation plant which is designed for the average waste water production over the entire year, the plant is equipped with an additionally connectable full load stage, composed of a trickling filter and downstream aerated auxiliary tank. The seasonal waste waters are prepurified in this by a multiple recirculation through the trickling filter and subsequent aeration in the auxiliary tank, with or without contact with the return sludge, with a degree of purification of e.g. 60 to 80%, before the waste waters, without intermediate clarification, are delivered to the light load activation stage for complete purification.

Treatment of Wastewater from a Detergent and Soap Factory - Case Study

Abstract: Effluent from a soap and detergent manufacturing plant was the subject of this study. Hazards created by this plant are due to the presence of considerable concentrations of detergents, oil and grease. In order to obtain the most economical system to provide a high quality effluent, an all-over management program was designed. Analysis of the wastewater discharged from the different manufacturing operations showed that major sources of pollution are wastes discharged from the saponification and sulfonation processes. In an attempt to reduce the organic load in the waste, recycling of these 2 wastes was carried out. This reduced the BOD & COD of the final effluent by 58% and 41% respectively. Coagulation and flocculation of the final effluent at the optimum doses of alum or ferric chloride was not successful. On the other hand, biological treatment using 2 models simulating activated sludge and trickling filter systems gave satisfactory results. Biokinetic coefficients y, Kd, K, and Ks were determined. Based on the findings of the laboratory model tests, a final process design was developed.

Pilot Plant Studies of Biological Phenol Degradation from Industrial Effluents.

Abstract: : A trickling filter pilot plant was operated to biologically degrade spent phenol paint stripper from building 507 at the Hill AFB Air Logistic Center in Ogden, Utah. The parameters studied were temperature, pH, diammonium phosphate concentration, air flow, influent flow rate, and phenol concentration. Also, series flow, recirculation, and a flooded reactor bed were tested. The pilot plant was operated successfully over a broad range of parameters and phenol removal was demonstrated at concentrations up to 2100 ppm of phenol. The microorganisms degraded phenol at a constant rate related to phenol concentration, and they exhibited physiological stability to the parameters tested. A respirometer test apparatus was used to screen the temperature, pH, and diammonium phosphate and phenol concentrations. The effects of the concentration of chromium and cadmium and those of mixed phenols on the respiration rate were also evaluated with the respirometer. Keywords: Solvent degradation; Waste minimization; Phenolic wastewater.

Surface and Spray Aeration

Abstract: Gas transfer in water and wastewater treatment is a process whereby water is brought into contact with air or a gas and, because of the presence of a concentration gradient, the transfer of gases to and/or from the water occurs. In water treatment, for example, aeration is used to remove carbon dioxide, hydrogen sulfide, methane, and various volatile organic compounds, and to oxidize iron and manganese in the water. In wastewater treatment, the gas transfer is used primarily in the activated sludge and trickling filtration processes and in aerated lagoons and aerobic digesters. Air or oxygen gas is supplied to the wastewater by air compressors and by mechanical aerators to induce a higher concentration gradient in the wastewater and thereby to accelerate oxygen transfer. The spray of wastewater by nozzles over trickling filter beds also results in an accelerated oxygen transfer. In polluted streams and lakes, oxygen transfer from the limitless atmosphere to the water occurs, also because of the existence of dissolved oxygen concentration (or deficit) gradient. This reaeration process is an important and essential element of the stream self-purification process.